[PATCH v21 28/39] ASoC: qcom: qdsp6: Add SOC USB offload select get/put callbacks

[Wesley Cheng <quic_wcheng@xxxxxxxxxxx>]

In order for device selection to be supported, the Q6USB backend DAI link
will need to be notified about the device to start the offloading session
on. Device selection is made possible by setting the Q6AFE device token.
The audio DSP utilizes this parameter, and will pass this field back to
the USB offload driver within the QMI stream requests.

Signed-off-by: Wesley Cheng <quic_wcheng@xxxxxxxxxxx>
---
 sound/soc/qcom/qdsp6/q6usb.c | 115 +++++++++++++++++++++++++++++++++--
 1 file changed, 111 insertions(+), 4 deletions(-)

diff --git a/sound/soc/qcom/qdsp6/q6usb.c b/sound/soc/qcom/qdsp6/q6usb.c
index 1e85636bc6cb..d83dbd10bdcc 100644
--- a/sound/soc/qcom/qdsp6/q6usb.c
+++ b/sound/soc/qcom/qdsp6/q6usb.c
@@ -36,9 +36,12 @@ struct q6usb_port_data {
 	struct q6afe_usb_cfg usb_cfg;
 	struct snd_soc_usb *usb;
 	struct q6usb_offload priv;
-	int active_usb_chip_idx;
+	struct mutex mutex;
 	unsigned long available_card_slot;
 	struct q6usb_status status[SNDRV_CARDS];
+	bool idx_valid;
+	int sel_card_idx;
+	int sel_pcm_idx;
 };
 
 static const struct snd_soc_dapm_widget q6usb_dai_widgets[] = {
@@ -54,10 +57,34 @@ static int q6usb_hw_params(struct snd_pcm_substream *substream,
 			   struct snd_soc_dai *dai)
 {
 	struct q6usb_port_data *data = dev_get_drvdata(dai->dev);
+	struct snd_soc_pcm_runtime *rtd = substream->private_data;
+	struct snd_soc_dai *cpu_dai = snd_soc_rtd_to_cpu(rtd, 0);
+	struct q6afe_port *q6usb_afe;
 	int direction = substream->stream;
+	int chip_idx;
+	int ret;
+
+	mutex_lock(&data->mutex);
+	chip_idx = data->status[data->sel_card_idx].sdev->chip_idx;
+
+	ret = snd_soc_usb_find_supported_format(chip_idx, params, direction);
+	if (ret < 0)
+		goto out;
+
+	q6usb_afe = q6afe_port_get_from_id(cpu_dai->dev, USB_RX);
+	if (IS_ERR(q6usb_afe))
+		goto out;
 
-	return snd_soc_usb_find_supported_format(data->active_usb_chip_idx,
-					params, direction);
+	ret = afe_port_send_usb_dev_param(q6usb_afe, data->sel_card_idx,
+						data->sel_pcm_idx);
+	if (ret < 0)
+		goto out;
+
+	data->status[data->sel_card_idx].pcm_index = data->sel_pcm_idx;
+out:
+	mutex_unlock(&data->mutex);
+
+	return ret;
 }
 
 static const struct snd_soc_dai_ops q6usb_ops = {
@@ -88,6 +115,70 @@ static struct snd_soc_dai_driver q6usb_be_dais[] = {
 	},
 };
 
+static int q6usb_get_offload_dev(struct snd_kcontrol *kcontrol,
+				 struct snd_ctl_elem_value *ucontrol,
+				 enum snd_soc_usb_kctl type)
+{
+	struct snd_soc_component *component = snd_kcontrol_chip(kcontrol);
+	struct q6usb_port_data *data = dev_get_drvdata(component->dev);
+	int idx;
+
+	mutex_lock(&data->mutex);
+
+	if (!data->available_card_slot) {
+		idx = -1;
+	} else {
+		if (type == SND_SOC_USB_KCTL_CARD_ROUTE)
+			idx = data->sel_card_idx;
+		else
+			idx = data->sel_pcm_idx;
+	}
+
+	ucontrol->value.integer.value[0] = idx;
+	mutex_unlock(&data->mutex);
+
+	return 0;
+}
+
+static int q6usb_put_offload_dev(struct snd_kcontrol *kcontrol,
+				 struct snd_ctl_elem_value *ucontrol,
+				 enum snd_soc_usb_kctl type)
+{
+	struct snd_soc_component *component = snd_kcontrol_chip(kcontrol);
+	struct q6usb_port_data *data = dev_get_drvdata(component->dev);
+	int changed = 0;
+	int idx;
+
+	idx = ucontrol->value.integer.value[0];
+
+	mutex_lock(&data->mutex);
+	switch (type) {
+	case SND_SOC_USB_KCTL_CARD_ROUTE:
+		if (idx >= 0 && test_bit(idx, &data->available_card_slot)) {
+			data->sel_card_idx = idx;
+			changed = 1;
+		}
+		break;
+	case SND_SOC_USB_KCTL_PCM_ROUTE:
+		if (idx >= 0 && data->sel_card_idx >= 0 &&
+		    idx < data->status[data->sel_card_idx].sdev->num_playback) {
+			data->sel_pcm_idx = idx;
+			changed = 1;
+		}
+		break;
+	default:
+		break;
+	}
+
+	if (changed)
+		data->idx_valid = true;
+
+out:
+	mutex_unlock(&data->mutex);
+
+	return changed;
+}
+
 static int q6usb_audio_ports_of_xlate_dai_name(struct snd_soc_component *component,
 					const struct of_phandle_args *args,
 					const char **dai_name)
@@ -117,16 +208,28 @@ static int q6usb_alsa_connection_cb(struct snd_soc_usb *usb,
 
 	data = dev_get_drvdata(usb->component->dev);
 
+	mutex_lock(&data->mutex);
 	if (connected) {
 		/* We only track the latest USB headset plugged in */
-		data->active_usb_chip_idx = sdev->card_idx;
+		if (!data->idx_valid) {
+			data->sel_card_idx = sdev->card_idx;
+			data->sel_pcm_idx = 0;
+		}
 
 		set_bit(sdev->card_idx, &data->available_card_slot);
 		data->status[sdev->card_idx].sdev = sdev;
 	} else {
 		clear_bit(sdev->card_idx, &data->available_card_slot);
 		data->status[sdev->card_idx].sdev = NULL;
+
+		if (data->sel_card_idx == sdev->card_idx) {
+			data->idx_valid = false;
+			data->sel_card_idx = data->available_card_slot ?
+					ffs(data->available_card_slot) - 1 : 0;
+			data->sel_pcm_idx = 0;
+		}
 	}
+	mutex_unlock(&data->mutex);
 
 	return 0;
 }
@@ -142,6 +245,8 @@ static int q6usb_component_probe(struct snd_soc_component *component)
 		return -ENOMEM;
 
 	usb->connection_status_cb = q6usb_alsa_connection_cb;
+	usb->put_offload_dev = q6usb_put_offload_dev;
+	usb->get_offload_dev = q6usb_get_offload_dev;
 
 	ret = snd_soc_usb_add_port(usb);
 	if (ret < 0) {
@@ -205,6 +310,8 @@ static int q6usb_dai_dev_probe(struct platform_device *pdev)
 
 	data->priv.domain = iommu_get_domain_for_dev(&pdev->dev);
 
+	mutex_init(&data->mutex);
+
 	data->priv.dev = dev;
 	dev_set_drvdata(dev, data);